:root {
  --bg-color-light: #ffffff;
  --text-color-light: #000000;
  --bg-color-dark: #121212;
  --text-color-dark: #ffffff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg-color: var(--bg-color-dark);
    --text-color: var(--text-color-dark);
  }
}

@media (prefers-color-scheme: light) {
  :root {
    --bg-color: var(--bg-color-light);
    --text-color: var(--text-color-light);
  }
}

body {
  margin: 0;
  font-family: "Noto Sans", "Noto Sans JP", "Noto Sans KR", "Noto Sans SC",
    "Noto Naskh Arabic", "Noto Serif Thai", Arial, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

.container {
  text-align: center;
}

h1 {
  font-size: 4rem;
  margin: 0;
}

.fade-out {
  opacity: 0;
  transition: opacity 0.5s ease-out;
}

.fade-in {
  opacity: 1;
  transition: opacity 0.5s ease-in;
}